1. Field of Invention
The present invention relates to an active roll control device of a vehicle. More particularly, the present invention relates to an active roll control device (ARCS: Active Roll Control System) that actively controls roll with a stabilizer bar that is disposed at both suspension arms through a stabilizer link.
2. Description of Related Art
Generally, a suspension system of a vehicle connects an axle with a vehicle body, and prevents vibration or impact that is transferred from the road from being transferred to the vehicle body while driving to enhance ride comfort.
The suspension system includes a chassis spring that reduces impact transferred from the road, a shock absorber that dampens free vibration of the chassis spring to improve ride comfort, and a stabilizer bar that reduces roll of a vehicle.
The stabilizer bar is fixed on a vehicle body and both end portions thereof are respectively fixed to a lower arm or a strut bar through a stabilizer link.
Accordingly, the stabilizer bar is not operated while left and right wheels are equally moved up/down and reduces roll of a vehicle body through a torsion elastic force while the left and right wheels are differently moved up/down.
FIG. 1 is a partial perspective view of a suspension system for a vehicle that uses an active roll control device according to a conventional art.
Referring to FIG. 1, an active roll control device of a conventional art improves a roll characteristic of a vehicle by varying rigidity of a stabilizer bar 1 according to a driving condition of a vehicle.
The active roll control device includes a stabilizer bar 1, a stabilizer link 3, a sliding unit 5 that is disposed on a lower arm 7 as a suspension arm, and a drive source 6.
The stabilizer bar 1 is mounted on a bracket 13 of a sub-frame 11 at a vehicle body side through a mounting bushing 15.
Also, one end of the stabilizer link 3 is connected to one end of the stabilizer bar 1 through a ball joint (BJ).
Meanwhile, an outer end portion of the lower arm 7 is connected to a lower side of a knuckle 17 and includes a housing portion 21 to form the sliding unit 5.
The sliding unit 5 includes a slide rail 23 at both sides of the inside of the housing portion 21 on the lower arm 7 in a vehicle width direction, and a connector 25 that is connected to a lower end of the stabilizer link 3 is disposed between the slide rail 23 to be guided in a vehicle width direction.
The drive source 6 includes a motor 19 having a drive shaft 27 that is operated in both directions and is disposed at one side of the sub-frame 11, and the drive shaft 27 is connected to the connector 25 through a push rod 29 to draw or push the connector 25.
The conventional active roll control device that is configured as described above adjusts a connection position of the stabilizer link 3 on the lower arm 7 through the operation of the motor 19 according to the driving condition of the vehicle, and actively controls the lever ratio of the stabilizer link 3 to adjust the roll rigidity and the turning stability of the vehicle.
Meanwhile, because the above active roll control device is disposed in a narrow space that is formed at a lower portion of a vehicle body, the system has to be compact, but frictional resistance of the sliding unit is a factor that deteriorates the size reduction of the drive source 6.
For this, recently there has been a demand for minimizing the frictional resistance between the connector 25 and the slide rail 23 of the sliding unit 5 such that power delivery efficiency of the motor 19 as a drive source is improved to enable the size reduction.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.